Summary:
The patch adds a class called `BlobFileReader` that can be used to retrieve blobs
using the information available in blob references (e.g. blob file number, offset, and
size). This will come in handy when implementing blob support for `Get`, `MultiGet`,
and iterators, and also for compaction/garbage collection.
When a `BlobFileReader` object is created (using the factory method `Create`),
it first checks whether the specified file is potentially valid by comparing the file
size against the combined size of the blob file header and footer (files smaller than
the threshold are considered malformed). Then, it opens the file, and reads and verifies
the header and footer. The verification involves magic number/CRC checks
as well as checking for unexpected header/footer fields, e.g. incorrect column family ID
or TTL blob files.
Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression
type passed by the caller (because of the presence of the header and footer, the
specified offset cannot be too close to the start/end of the file; also, the compression type
has to match the one in the blob file header), and retrieves and potentially verifies and
uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set,
`BlobFileReader` reads the blob record header as well (as opposed to just the blob itself)
and verifies the key/value size, the key itself, as well as the CRC of the blob record header
and the key/value pair.
In addition, the patch exposes the compression type from `BlobIndex` (both using an
accessor and via `DebugString`), and adds a blob file read latency histogram to
`InternalStats` that can be used with `BlobFileReader`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D23999219
Pulled By: ltamasi
fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
Summary:
The patch makes sure that the functionality required for the new integrated
BlobDB implementation (most importantly, the classes related to reading and
writing blob files) is also built in LITE mode by removing the corresponding
`#ifndef`s.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7272
Test Plan: Ran `make check` in both regular and LITE mode.
Reviewed By: zhichao-cao
Differential Revision: D23173280
Pulled By: ltamasi
fbshipit-source-id: 1596bd1a76409a8a6d83d8f1dbfe08bfdea7ffe6
Summary:
When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433
Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag.
Differential Revision: D19977691
fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
Summary:
The patch adds a new command line parameter --decode_blob_index to sst_dump.
If this switch is specified, sst_dump prints blob indexes in a human readable format,
printing the blob file number, offset, size, and expiration (if applicable) for blob
references, and the blob value (and expiration) for inlined blobs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5926
Test Plan:
Used db_bench's BlobDB mode to generate SST files containing blob references with
and without expiration, as well as inlined blobs with and without expiration (note: the
latter are stored as plain values), and confirmed sst_dump correctly prints all four types
of records.
Differential Revision: D17939077
Pulled By: ltamasi
fbshipit-source-id: edc5f58fee94ba35f6699c6a042d5758f5b3963d
Summary:
This is groundwork for adding garbage collection support to BlobDB. The
patch adds logic that keeps track of the oldest blob file referred to by
each SST file. The oldest blob file is identified during flush/
compaction (similarly to how the range of keys covered by the SST is
identified), and persisted in the manifest as a custom field of the new
file edit record. Blob indexes with TTL are ignored for the purposes of
identifying the oldest blob file (since such blob files are cleaned up by the
TTL logic in BlobDB).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5903
Test Plan:
Added new unit tests; also ran db_bench in BlobDB mode, inspected the
manifest using ldb, and confirmed (by scanning the SST files using
sst_dump) that the value of the oldest blob file number field matches
the contents of the file for each SST.
Differential Revision: D17859997
Pulled By: ltamasi
fbshipit-source-id: 21662c137c6259a6af70446faaf3a9912c550e90
Summary:
Adding the `min_blob_size` option to allow storing small values in base db (in LSM tree) together with the key. The goal is to improve performance for small values, while taking advantage of blob db's low write amplification for large values.
Also adding expiration timestamp to blob index. It will be useful to evict stale blob indexes in base db by adding a compaction filter. I'll work on the compaction filter in future patches.
See blob_index.h for the new blob index format. There are 4 cases when writing a new key:
* small value w/o TTL: put in base db as normal value (i.e. ValueType::kTypeValue)
* small value w/ TTL: put (type, expiration, value) to base db.
* large value w/o TTL: write value to blob log and put (type, file, offset, size, compression) to base db.
* large value w/TTL: write value to blob log and put (type, expiration, file, offset, size, compression) to base db.
Closes https://github.com/facebook/rocksdb/pull/3066
Differential Revision: D6142115
Pulled By: yiwu-arbug
fbshipit-source-id: 9526e76e19f0839310a3f5f2a43772a4ad182cd0
Yanqin Jin